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Effects of Electron Bombardment on Elasticity and Mechanical Damping of Certain Glasses
Author(s) -
BARBER S. W.,
FORRY K. E.,
DEGERING D. F.
Publication year - 1960
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1960.tb13684.x
Subject(s) - borosilicate glass , materials science , electron , elasticity (physics) , silicate glass , composite material , thermodynamics , mineralogy , chemistry , physics , quantum mechanics
A borosilicate glass and a lead‐containing silicate glass have been exposed to various dosages of 2‐m.e.v. electrons, and the effects on the logarithmic decrement and period of a freely oscillating torsional pendulum in which each was made the torsional member have been noted. These effects, in both glasses, are qualitatively described as disannealing. Quantitatively, tan δ was increased 10 to 15% in the borosilicate and 30 to 60% in the lead glass, and the corresponding decreases in rigidity were of the order of 0.4 and 2%, respectively. In both glasses the mechanical effects and the associated brownish color anneal out in about 20 hours at 500°F. Besides these effects, there were some completely unexpected effects which are reported here for the first time and should be verified by others. These consist of (1) changes in the shape of tan δ vs. temperature curves caused not only by thermal treatment but also by changes in period of the pendulum and (2) fine structure in the tan δ vs. temperature maxima due to sodium ion diffusion. These details complicate the interpretation of such maxima and, if verified, will justify a re‐examination of the anelastic behavior of glasses in general and borosilicate glasses in particular.